CN113017539A

CN113017539A - Endoscope and method of manufacturing endoscope

Info

Publication number: CN113017539A
Application number: CN202110295224.XA
Authority: CN
Inventors: 马立克·瑟克沃斯基
Original assignee: Research Development International Corp
Current assignee: Research Development International Corp
Priority date: 2014-10-20
Filing date: 2016-02-08
Publication date: 2021-06-25
Also published as: CN108024697A; WO2016064763A1; EP3209233A4; WO2016171780A1; EP3285633A4; WO2016064449A1; EP3285633A1; US20180228346A1; EP3209192A4; HK1247797A1; CN107529958A; HK1244652A1; CN107529958B; EP3209192A1; US20210290039A1; EP3209233B1; US20230240520A1; US11103127B2; CN107567301B; US11540703B2

Abstract

An endoscope and a method of manufacturing an endoscope, wherein the endoscope comprises: a tubular elongate member; a tension wire disposed in the tension lumen along one side of the elongate member between the proximal and distal ends of the elongate member; a head disposed at a distal end of the elongated member and comprising: a tubular tension ring attached to a distal end of the tension wire, the tension ring having the same outer diameter as the elongated member; wherein the tubular sheath is fitted over the elongate member and the tensioning ring of the head; the proximal end of the tension ring is adjacent to the distal end of the elongated member; the tensioning lumen of the elongate member is a longitudinal groove cut into the outer surface of the elongate member; the tension wires are held in the groove by a tubular sheath.

Description

Endoscope and method of manufacturing endoscope

Cross Reference to Related Applications

The present invention is a divisional application of a patent application having an application date of 2016, 2/8, and an application number of CN201680028488.6, entitled "steerable micro-endoscope".

The present invention claims priority from PCT application PCT/US2015/027170 entitled "stereo MICRO-endo scope" filed on 22.4.2015, which is incorporated herein by reference; and this PCT application claims priority to USSN 62/066,340 filed on 20/10/2014, which is also incorporated herein by reference.

The present invention claims priority from PCT application PCT/US2015/056279 entitled "STEERABLE MICRO-ENDOSCOPE" (stereo MICRO-ENDOSCOPE), filed on 19/10/2015, which is incorporated herein by reference.

Technical Field

The present invention relates to a steerable micro-device, such as a reduced size endoscope, for example for medical use, and a method of manufacturing the same.

Background

Various endoscopes are commercially available for introducing various surgical tools, fluids such as radiographic materials, angioplasty balloons, fiberoptic scopes, laser lights, and cutting instruments into vessels and cavities within the body. In addition, various techniques and systems have been developed to guide or steer catheters in vessels and cavities in the body to use these tools, fluids, and other materials.

Examples of such guidance or control techniques and systems for catheters or endoscopes can be seen in the following: in U.S. patent US5,342,299 entitled "stable separator" to Snoke; in WO2004086957 to Banik entitled "Single use endoscopic imaging System"; in US20140135576 entitled "coaxil micro-endoscope" to Hebert; in US8,517,921 entitled "Endoscopic induced reduced diameter leaf craft" to Tremaglio; in Bakos, US8,262,563 entitled "Endoscopic transparent insulating cover"; in U.S. Pat. No. 4, 8,320,650 entitled "In vivo spectral micro-imaging of tissue" by Demos; in Chong, part US2008/031941 entitled "the winter Device"; in WO 02/053221 entitled "Deflectible Guiding Apparatus" by Garber; in US4,580,551 entitled "Flexible Plastic Tube for Endoscope and the Like" to Siegmund; in U.S. Pat. No. 5,325,845 to Adair entitled "Steerable shear for Use with Selected Removable Optical Cable"; giesy in US4,798,193 entitled "Protective Shell Instrument Carrier"; in US4,788,967 entitled "Endoscope" by Ueda; in US7,033,317 entitled "dispersible end vector and method of marking a dispersible end vector" by Pruitt; in US5,197,457 entitled "formable and removable shear for optical connectors" by Adair.

However, there is a need for a steerable micro device, such as a micro endoscope having a steerable distal end, which will be particularly simple and economical to manufacture.

Disclosure of Invention

The object of the present invention relates to a steerable micro-endoscope, preferably comprising an optical fiber for directing light to its distal end, and comprising a camera or imaging sensor at its distal end. Preferably, the camera or imaging sensor has a rectangular or square cross-section and comprises a rectangular or square CMOS or CCD sensor.

The object of the present invention relates to a microdevice which is steerable in that it has an elongated member with a distal portion that is bent in a remote control manner. The elongate member may also be arranged to rotate axially in a controlled manner.

The object of the present invention relates to a miniature endoscope having an elongated member with a diameter of 2mm or less; preferably 1.5mm or less.

These and other objects, features and advantages are provided in an endoscope comprising: a tubular elongated member having a longitudinal axis, a proximal end, and a distal end; at least one tensioning wire disposed within a tensioning lumen along one side of the elongate member between the proximal and distal ends of the elongate member; a head disposed at a distal end of the elongated member, the head comprising: a tubular tension ring attached to a distal end of the tension wire, the tension ring having the same outer diameter as the elongate member; an imaging sensor having a rectangular cross-section disposed at a distal end of the head; and a tubular distal housing disposed longitudinally around the imaging sensor, the distal housing having an inner diameter that is the same or slightly larger than a diagonal of the rectangular cross-section of the imaging sensor; wherein the tubular sheath is fitted over the elongate member and the tensioning ring of the head. According to one embodiment of the invention, "slightly larger" may mean up to 10 microns. According to one embodiment of the invention, "slightly larger" may mean up to 5 microns. According to one embodiment of the invention, "slightly larger" may mean up to 2.5 microns.

According to one embodiment of the invention, the distal housing of the head has the same outer diameter as the outer diameter of the tubular sheath.

According to one embodiment of the invention, the distal ends of the plurality of optical fibers are disposed between the inner diameter of the distal housing and the sidewall of the imaging sensor; the optical fiber passes through a lumen in the tension ring and a lumen in the elongate member.

According to one embodiment of the invention, the distal housing has a proximal end attached to the distal end of the tension ring; the proximal end of the tension ring is adjacent to the distal end of the elongated member.

According to one embodiment of the invention, the tension ring includes a longitudinal slit extending from a proximal end of the tension ring; the distal ends of the tension wires are along the longitudinal cut and welded thereto so that the tension wires do not extend radially beyond the outer diameter of the tension ring.

According to one embodiment of the invention, the tensioning lumen of the elongate member is a longitudinal groove cut into the outer surface of the elongate member; the tension wires are held in the grooves by the tubular sheath.

According to one embodiment of the invention, the elongate member comprises a central lumen; the central lumen has a narrower cross section opposite the longitudinal groove in the outer surface of the elongate member.

According to one embodiment of the invention, the elongated member comprises two tensioning lumens and two tensioning wires arranged symmetrically with respect to the longitudinal axis of the elongated member.

According to one embodiment of the invention, the distal housing is formed by the distal end of the tubular sheath; a tubular sheath encasing the elongated member, the tensioning ring of the head, and the imaging sensor; the proximal end of the tension ring is adjacent to the distal end of the elongated member.

According to one embodiment of the invention, the elongated member comprises two longitudinal tensioning lumens and two tensioning wires arranged symmetrically with respect to the longitudinal axis of the elongated member.

According to one embodiment of the invention, the tension ring comprises: two longitudinal recesses cut in the inner wall of the tension ring and aligned with the longitudinal tension lumens of the elongated member; and two radial recesses connecting the longitudinal recess to a circumferential outer groove cut in the outer wall of the tensioner ring; the distal ends of the two tension wires are arranged in the two longitudinal recesses and the two radial recesses and are connected in the circumferential outer groove.

According to one embodiment of the invention, the thickness of the elongated member forms a longitudinal tensioning lumen of the tubular elongated member.

According to one embodiment of the invention, the elongate member comprises a central lumen; the central lumen has a narrower cross-section adjacent the longitudinal tensioning lumen.

According to one embodiment of the invention, the distal portion of the elongate member has a first hardness; a portion of the elongate member between the distal portion and the proximal end of the elongate member has a second durometer that is higher than the first durometer.

According to one embodiment of the invention, the elongated member is made of a single material; the distal portion of the elongate member includes a series of cuts or recesses that are portions of the elongate member removed along the tensioning lumen along a plane that is generally perpendicular to the longitudinal axis of the elongate member.

One embodiment of the present invention is also directed to a method of manufacturing an endoscope, comprising: providing an imaging sensor having a rectangular cross-section; connecting a proximal end of the imaging sensor to an imaging cable; providing a tension ring having an outer diameter equal to a diagonal of the rectangular cross-section, the ring having a central longitudinal lumen capable of receiving the imaging cable; providing a flexible elongate member having an outer diameter equal to the diagonal of the rectangular cross-section, the flexible elongate member having at least a central longitudinal lumen capable of receiving the imaging cable and at least one lateral longitudinal tensioning lumen capable of receiving a tensioning wire; attaching a distal end of a tension wire to the tension ring; passing the tension wire through the at least one tension lumen until a tension ring is disposed at a distal end of the flexible elongate member; introducing the ring and the elongate member into an axial lumen of a flexible tubular sheath, wherein the sheath has an inner diameter equal to or slightly larger than the diagonal of the rectangular cross-section, such that the ring is located inside the flexible tubular sheath beyond the distal end of the flexible tubular sheath; passing the imaging cable through the longitudinal lumen of the ring and through the longitudinal lumen of the flexible elongate member from the distal end of the flexible tubular sheath; introducing the imaging sensor into an axial lumen of a distal end of the flexible tubular sheath.

According to an embodiment of the invention, the method further comprises: passing proximal ends of a plurality of optical fibers through a space contained between a wall of an imaging sensor and an inner wall of the flexible tubular sheath and then through a longitudinal lumen ring and an elongate member; arranging distal ends of the plurality of optical fibers to extend longitudinally in the space along the imaging sensor; and permanently attaching distal ends of the plurality of optical fibers in the space.

According to an embodiment of the invention, the method further comprises: polishing the distal ends of a plurality of optical fibers attached to an imaging sensor with a distal end optical window of the imaging sensor.

One embodiment of the present invention is also directed to a method of manufacturing an endoscope, comprising: providing an imaging sensor having a rectangular cross-section with a proximal end of the imaging sensor connected to an imaging cable; providing a tubular housing having an inner diameter equal to or slightly larger than the diagonal of said rectangular cross-section; a proximal end of a tubular housing attached to a distal end of a tensioning ring, an outer diameter of the tensioning ring being an outer diameter of the tubular housing, and the tensioning ring having a central longitudinal lumen configured to receive the imaging cable; providing a flexible elongate member having an outer diameter equal to an outer diameter of the tensioner ring, the flexible elongate member having at least a central longitudinal lumen capable of receiving the imaging cable and at least one lateral longitudinal tensioning lumen capable of receiving a tensioning wire; attaching a distal end of a tension wire to the tension ring; passing the tension wire through the at least one tension lumen; introducing the ring and the elongate member into an axial lumen of a flexible tubular sheath, wherein the sheath has an inner diameter equal to or slightly larger than the outer diameter of the ring and the elongate member; passing the imaging cable through the longitudinal lumens of the tensioning ring and flexible elongate member; and introducing the imaging sensor into the tubular housing.

According to one embodiment of the invention, the outer diameter of the sheath is equal to the outer diameter of the tubular housing.

According to an embodiment of the invention, the method further comprises: passing the proximal ends of the plurality of optical fibers through a space contained between a wall of the imaging sensor and an inner wall of the tubular housing and then through the longitudinal lumen of the ring and the elongate member; arranging distal ends of the plurality of optical fibers longitudinally along an imaging sensor in the space; and permanently attaching the distal ends of the plurality of optical fibers in the space.

According to an embodiment of the invention, the method further comprises polishing said distal ends of a plurality of optical fibers attached to the imaging sensor together with a distal optical window of the imaging sensor.

One embodiment of the present invention is also directed to an endoscope comprising a cylindrical elongated member having a distal end and a proximal end, the elongated member comprising at least a first lumen and a second lumen, a first tensioning wire extending in the first lumen and a tensioning wire extending in the second lumen, a distal end of the tensioning wire attached at the distal end of the elongated member and a proximal end of the tensioning wire exiting the lumen at the proximal end of the elongated member; the elongate member and the first and second lumens are arranged such that: the distal portion of the elongate member bends in a first direction when the proximal end of the first tensioning wire is pulled and bends in a second direction when the proximal end of the second tensioning wire is pulled; wherein the proximal end of the elongated member is coupled to the handle, the handle and the elongated member forming a T-shaped arrangement, wherein the legs of the T are the elongated members and the head of the T is the handle; the handle comprises a lever arranged such that: compressing a first portion of the handle on a proximal side of the elongate member, pulling a first tensioning wire; and compressing a second portion of the handle on the other side of the proximal end of the elongate member, pulling on the second tensioning wire.

According to one embodiment of the invention, the shape of the handle is such that: the handle may be held in a user's hand with the elongate member passing between two fingers of the user's hand; wherein, one side of the hand close to the index finger fastens the handle on the handle and compresses the first part of the handle; the side of the hand near the little finger fastens the handle on the handle and compresses the second part of the handle.

Drawings

FIG. 1 is a front view of an endoscope according to one embodiment of the present invention.

FIG. 2 is a front view of an endoscope, connected to an imaging device and a power source, according to one embodiment of the present invention.

FIG. 3 is an elevation view, partially in section, of a distal portion of an endoscope sheathed elongate member, according to one embodiment of the invention.

Fig. 4 is an elevation view, partially in cross-section, of a distal portion of the elongate member of the sheath shown in fig. 3.

FIG. 5 is an elevation view, partially in section, of a distal portion of an endoscope sheathed elongate member, according to one embodiment of the invention.

Fig. 6 is an elevation view, partially in cross-section, of a distal portion of the sheathed elongate member shown in fig. 5.

Fig. 7 is a front view of a distal housing attached to a tension ring, according to an embodiment of the present invention.

Fig. 8 includes a side, front, and cross-sectional view of a distal housing attached to a tension ring, according to an embodiment of the invention.

Fig. 9 is a top view of a distal housing attached to a tension ring as shown in fig. 8 and attached to a tension wire according to one embodiment of the invention.

Fig. 10 includes a front view and a cross-sectional view of a distal housing attached to a tension ring as shown in fig. 8 and attached to a tension wire in accordance with an embodiment of the present invention.

Fig. 11 includes side, front, and cross-sectional views of a distal housing attached to a tension ring according to an embodiment of the present invention.

Fig. 12 includes a front view and a cross-sectional view of a distal housing attached to a tension ring as shown in fig. 11 and attached to a tension wire in accordance with an embodiment of the present invention.

Fig. 13 shows an axial cross-section of the elongated member as shown in fig. 3 and 4.

Fig. 14 shows an axial cross-section of the elongated member as shown in fig. 5 and 6.

Fig. 15A and 15B illustrate the process of attaching the distal end of an optical fiber to an imaging sensor, according to one embodiment of the invention.

Fig. 16A is a front view of a tubular tensioner ring such as that shown in fig. 3 and 4.

Fig. 16B includes a side view and a cross-sectional view of the tubular tensioner ring of fig. 16A.

FIG. 17 includes bottom views of distal portions of sheathed elongate members of two endoscopes according to an embodiment of the present invention.

Fig. 18 is a tissue diagram describing a method of manufacturing the endoscope shown in fig. 3.

FIG. 19 is an organizational chart depicting possible additional steps of the method shown in FIG. 18.

Fig. 20 is a tissue diagram describing a method of manufacturing the endoscope shown in fig. 5.

FIG. 21 is an organizational chart depicting possible additional steps of the method shown in FIG. 20.

FIG. 22 is a front view of a steerable micro-device or endoscope according to one embodiment of the present invention.

Fig. 23 is a partially open view of the steerable micro-device or endoscope as shown in fig. 22.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough description of various embodiments disclosed herein. However, it will be understood by those skilled in the art that the presently claimed invention may be practiced without all of the specific details discussed below. In other instances, well-known features have not been described in order not to obscure the present invention. Like reference numerals refer to like elements in the drawings.

FIG. 1 is an elevation view of a steerable micro-device or endoscope 10 according to one embodiment of the present invention, including a sheathed elongate member 12 having a distal end and a proximal end; the proximal end of the sheath elongate member 12 is attached to a base 14. According to one embodiment of the invention, the base 14 is rotatable relative to the proximal housing 16 about the longitudinal axis of the sheathed elongate member, and the proximal housing 16 may comprise a handle 18. According to one embodiment of the invention, the base 14 is coupled to a knob 20 to allow for controllable rotation of the base 14, and the handle 18 includes a trigger 22 that allows for controllable pulling of one or more tensioning wires in the sheathed elongate member. In one embodiment, a trigger 22 is provided for pivoting in two directions, wherein pivoting the trigger in each of the two directions will pull on each of the two tension wires, the trigger 22 may include a lock for locking the tension wires stretched along the desired length. Knob 20 may include a lock for controllably locking base 14 for rotation through a desired angle.

According to one embodiment of the invention, the housing 16 is provided for receiving a cable 24 for providing light and/or power to the endoscope and for receiving visualization data from an imaging sensor disposed at the distal end of the sheathed elongate member, as described in detail.

Implementation details of the housing, the tensioned wire drive structure and the rotating structure of the ENDOSCOPE 10 and the sheathed elongate member 12 can be found, for example, in PCT application PCT/US2015/027170 entitled "sterile MICRO-ENDOSCOPE", filed on 22/4/2015, and incorporated herein by reference.

Typically, the distal portion of the sheathed elongate member is configured to: is readily compressible in at least one plane including the longitudinal axis of the elongate member and contains tension wires; when the tension wire is pulled proximally, the distal portion of the sheathed elongate member will begin to compress first before the portion of the proximal end having the lower compressibility is compressed, which will result in a more compressible portion to compress around the tension wire and bend because the tension wire is not in the center of the elongate member, but in the tension lumen on one side of the elongate member. The amount of bending is directly proportional to the force applied to the wire, the ratio of stiffness between the compressible portion and the less compressible portion of the elongated member, and the distance the wire is pulled by the center of the protrusion/elongated member. Such an embodiment allows 360 ° of distal end movement of the elongate member in conjunction with rotation of the elongate member. The torque braided sheath is disposed about the elongate structural elements and helps to provide a rotational response of the sheathed elongate structural elements to torsional forces without compromising the flexibility of the sheathed elongate structural elements. A microendoscope according to one embodiment of the present invention can be used for diagnostics in minimally invasive surgery, in many cases eliminating the need for expensive MRI. In contrast to procedures performed in hospitals under general anesthesia, the same microendoscope can be equipped with tools for performing minimally invasive surgical biopsies in the physician's office, requiring only local anesthesia. The elongate member may be made more or less compressible by using materials of different hardness or by using a single material in which recesses are cut or hollowed out to make the material more compressible.

Fig. 2 is a perspective view illustrating endoscope 10 connected to an imaging device 26 and to a power source and/or light source 28 for providing light and/or power, the imaging device 26 for displaying imaging data acquired at the distal end of the sheathed elongate member 12.

FIG. 3 is an elevation view, partially in section, of a distal portion 30 of a sheathed elongate member 12 of an endoscope 10 (not shown) according to one embodiment of the invention. According to one embodiment of the invention, the sheathed elongate member 12 has a longitudinal axis 32 and comprises a tubular (i.e. having a longitudinal lumen 31) elongate member 33 having a distal end 34 and a proximal end 36.

According to one embodiment of the present invention, at least one tensioning wire 38 is disposed in a tensioning lumen 40 along one side of the elongate member 33 between the proximal end 34 and the distal end 36 of the elongate member 33.

According to one embodiment of the invention, the elongated member 33 comprises two longitudinal tensioning lumens 40 and two tensioning wires 38 arranged symmetrically with respect to the longitudinal axis 32. According to one embodiment of the invention, the elongated member 33 may also include more than two longitudinal tensioning lumens and a corresponding number of tensioning wires.

According to one embodiment of the invention, the distal portion 30 of the sheathed elongate member 12 comprises a head 42 disposed at the distal end 34 of the elongate member 33, the head comprising: a tubular tension ring 44 attached to the distal end 46 of the tension wire 38, the tension ring 44 having the same outer diameter as the elongated member 33.

According to one embodiment of the invention, the tension ring 44 comprises two longitudinal recesses 48 cut in the inner wall of the tension ring 44 and aligned with the longitudinal tensioning lumens 40 of the elongated member 33, and two axial recesses 50 connecting the longitudinal recesses to a circumferential outer groove 52, the circumferential outer groove 52 being cut in the outer wall of the tension ring 44. According to one embodiment of the invention, the distal ends 46 of the two tensioning wires 38 are arranged in two longitudinal recesses 48 and two axial recesses 50 and are connected in the circumferential outer groove 52.

According to one embodiment of the invention, the thickness of the elongated member 33 forms a longitudinal tensioning lumen 40 of the tubular elongated member 33. As previously mentioned, according to one embodiment of the present invention, the elongated member 33 includes a central lumen 31. According to one embodiment of the invention, the central lumen 31 has a narrower cross-section in the vicinity of the longitudinal tensioning lumen 40.

According to one embodiment of the invention, the head 42 further comprises an imaging sensor 54 having a rectangular cross-section, arranged at the distal end of the head 42; and a tubular distal housing 56 disposed longitudinally around imaging sensor 54. According to one embodiment of the present invention, distal housing 56 has an inner diameter that is the same or slightly larger than the diagonal of the rectangular cross-section of imaging sensor 54. According to one embodiment of the invention, a tubular sheath 58 encases the elongated member 33 and the head's tension ring. According to one embodiment of the invention, the inner diameter of the tubular sheath 58 is equal to or slightly larger than the outer diameter of the elongated member 33 and the head's tensioning ring. According to one embodiment of the invention, the distal housing 56 of the head has the same outer diameter as the outer diameter of the tubular sheath 58. According to one embodiment of the invention shown in fig. 3, the distal housing 56 of the head is formed by the distal end of a tubular sheath 58. Thus, in the embodiment of the invention shown in FIG. 3, the total diameter of the sheathed elongate member 12 is equal to the diagonal of the imaging sensor 54 plus twice the wall thickness of the sheath 58. The jacket 82 may include a torque mesh. If desired, glue may be used to hold the imaging sensor in the sheath 82.

According to one embodiment of the present invention, the distal ends of a plurality of optical fibers 60 extending longitudinally along the imaging sensor 54 are disposed between the inner diameter of the distal housing 56 and a sidewall 62 of the imaging sensor 54; the optical fiber 60 passes through the lumen 64 in the tension ring 44 and the lumen 31 in the elongated member 33. For clarity, three optical fibers 60 are shown on each side 62 of imaging sensor 54 in FIG. 3, but according to one embodiment of the invention, up to several hundred optical fibers may be disposed on a side 62 of imaging sensor 54.

According to one embodiment of the invention, the distal end of the optical fiber 60 may be attached to the side 62 of the imaging sensor 54 by:

arranging said distal end of the optical fiber 60 in the space between the wall 62 of the imaging sensor 54 and the inner wall of an installation tube having an inner diameter equal to said diagonal of said rectangular cross-section; permanently attaching the distal end of the optical fiber 60 to the imaging sensor 54, for example by introducing glue or resin in the space existing between the fibers; and removing the mounting tube when the glue or resin is cured.

According to one embodiment of the invention, after imaging sensor 54 is attached to imaging sensor 54, the distal end of optical fiber 60 may be polished together with the distal end of imaging sensor 54 (e.g., including an optical window).

Fig. 4 is a partially cut-away, front view of the distal portion 30 of the sheathed elongate member 12 shown in fig. 3, showing elements spaced apart from one another for clarity.

Thus, fig. 4 more clearly shows the tubular elongate member 33 having a longitudinal lumen 31, a distal end 34 and a proximal end 36.

Fig. 4 also more clearly shows the tension wires 38 disposed in the tension lumen 40 along the sides of the elongate member 33, between the proximal and distal ends 34, 36 of the elongate member 33.

Fig. 4 also more clearly shows a tubular tensioner ring 44 attached to the distal end 46 of the tensioner wire 38, having two longitudinal recesses 48 (one shown) and two axial recesses 50 (one shown) cut in the inner wall of the tensioner ring 44 and aligned with the longitudinal tensioning lumen 40 of the elongated member 33, the two axial recesses 50 and the longitudinal recesses 48 connecting to a circumferential outer groove 52 cut in the outer wall of the tensioner ring 44.

Fig. 4 also more clearly shows the imaging cable 49 attached to the proximal end of the imaging sensor 54, which passes through the longitudinal lumen 64 of the ring 44 and the longitudinal lumen 31 of the elongate member 33 towards the proximal end of the elongate member. According to one embodiment of the invention, the imaging cable 49 may be disposed in the middle of the optical fiber 60, with the optical fiber 60 also passing through the longitudinal lumen of the loop 44 and the longitudinal lumen 31 of the elongated member 33 toward the proximal end of the elongated member 33.

Fig. 4 also more clearly shows that the central lumen 31 of the elongated member 33 has a narrower cross-section in the vicinity 66 of the longitudinal tensioning lumen 40.

According to one embodiment of the invention, the distal portion 68 of the elongated member 33 has a first durometer and a portion 69 of the elongated member 33 between the distal portion 68 and the proximal end 36 of the elongated member 33 has a second durometer that is higher than the first durometer. According to one embodiment of the invention, the elongate member 33 may be made of a single material, with the distal portion of the elongate member 33 including a series of cuts or recesses 70, with portions of the elongate member 33 removed along the tensioning lumen 40 along a plane generally perpendicular to the longitudinal axis 32 of the elongate member 33.

Details regarding other embodiments of elongated members having two degrees of stiffness may be found in PCT application PCT/US2015/027170 entitled "steel MICRO-end" filed on 22.4.2015, which is incorporated herein by reference.

FIG. 5 is an elevation view, partially in section, of a distal portion of a sheathed elongate member 12 of an endoscope 10 (not shown) according to another embodiment of the invention. According to one embodiment of the invention, the sheathed elongate member 12 has a longitudinal axis 32 and comprises a tubular (i.e. having a longitudinal lumen) elongate member 33 having a distal end 34 and a proximal end 36.

According to one embodiment of the present invention, at least one tensioning wire 38 is disposed in the tensioning lumen 72 along one side of the elongate member 33 between the proximal end 34 and the distal end 36 of the elongate member 33.

According to one embodiment of the invention, the elongated member 33 includes two longitudinal tensioning lumens 72 (one shown) and two tensioning wires 38 (one shown) symmetrically arranged with respect to the longitudinal axis 32. According to one embodiment of the invention, the elongated member 33 may also include more than two longitudinal tensioning lumens and a corresponding number of tensioning wires.

According to one embodiment of the invention, the distal portion of the sheathed elongate member 12 comprises a head 74 arranged at the distal end 34 of the elongate member 33, the head 74 comprising: a tubular tension ring 76 attached to a distal end 78 of each tension wire 38, the tension ring 76 having the same outer diameter as the elongated member 33. According to one embodiment of the invention, the tension ring 76 includes a longitudinal slit 80 for each tension wire extending from the proximal end of the tension ring and disposed in alignment with the tension lumen 72. According to one embodiment of the invention, the distal end 78 of each tensioning wire 38 is along and welded to a respective longitudinal cut 80. Preferably, the distal ends 78 of the tension wires are welded in the cut-outs 80 so that the tension wires do not extend radially beyond the outer diameter of the tension ring 76.

According to one embodiment of the invention, each tensioning lumen 72 of the elongate member 33 comprises a longitudinal groove cut in the outer surface of the elongate member 33; the tension wires are held in the grooves by a tubular sheath 82 that encases the elongate member 33.

According to one embodiment of the invention, the head 74 further comprises an imaging sensor 84 having a rectangular cross-section, which is arranged at the distal end of the head 74; and a tubular distal housing 86 disposed longitudinally around the imaging sensor 84, the distal housing 86 having an inner diameter that is the same as the diagonal of the rectangular cross-section of the imaging sensor 84.

According to one embodiment of the invention, the distal housing 86 has a proximal end attached to the distal end of the tension ring 76; the proximal end of the tension ring 76 abuts the distal end 34 of the elongated member 33.

According to one embodiment of the invention, a tubular sheath 82 encases the elongated member 33 and the tensioning ring 76 of the head 74. According to one embodiment of the invention, the outer diameter of the distal housing 86 of the head 74 is the same as the outer diameter of the tubular sheath 82.

Thus, in the embodiment of the invention shown in FIG. 5, the total diameter of the sheathed elongate member 12 is equal to the diagonal of the imaging sensor 84 plus twice the wall thickness of the distal housing 86. According to one embodiment of the invention, the walls of distal housing 86 may be thinner than the walls of sheath 82. The sheath 82 may include a torque mesh. According to one embodiment of the invention, the inner diameter of the distal housing 86 may be equal to the outer diameter of the tension ring 76, and the distal portion of the tension ring 76 may be introduced to the proximal portion of the distal housing 86 before permanently attaching (e.g., welding) the two portions.

According to one embodiment of the present invention, the distal ends of a plurality of optical fibers 88 extending longitudinally along the imaging sensor 84 are disposed between the inner diameter of the distal housing 86 and a sidewall 90 of the imaging sensor 84; the optical fiber 88 passes through a lumen 92 in the tension ring 76 and a lumen in the elongated member 33. For clarity, three optical fibers 88 are shown on each side 90 of the imaging sensor 84 in FIG. 5, but according to one embodiment of the invention, up to several hundred optical fibers may be disposed on the side 90 of the imaging sensor 84.

According to one embodiment of the invention, the distal end of the optical fiber 88 may be attached to the side 90 of the imaging sensor 84 by:

disposing the distal end of the optical fiber 88 in a space between a wall 90 of the imaging sensor 84 and an inner wall of the distal housing 86; and the distal end of the optical fiber 88 is permanently attached to the imaging sensor 84, for example by introducing glue or resin in the space existing between the fibers and allowing the glue or resin to set.

According to one embodiment of the invention, after the imaging sensor 84 is attached to the imaging sensor 84, the distal end of the optical fiber 88 is polished along with the distal end of the imaging sensor 84 (e.g., including an optical window).

Fig. 6 is an elevation view, partially in section, of the distal portion of the sheathed elongate member 12 shown in fig. 5, showing elements spaced apart from one another for clarity.

Thus, fig. 6 more clearly shows the tubular elongate member 33 having a longitudinal lumen 94, a distal end 34 and a proximal end 36.

Fig. 6 also more clearly shows that the tensioning wires 38 are disposed in the tensioning lumens 72 along the sides of the elongated member 33, between the proximal and distal ends 34, 36 of the elongated member 33.

Fig. 6 also more clearly shows a tubular tension ring 76 attached to the distal end 78 of the tension wire 38, having two longitudinal recesses 80 (one shown) cut through the wall of the tension ring 76 and aligned with the longitudinal tension lumens 72 (one shown).

Fig. 6 also more clearly shows that an imaging cable 95 attached to the proximal end of the imaging sensor 84 passes through the longitudinal lumen of the ring 76 and the longitudinal lumen 94 of the elongate member 33, towards the proximal end of the elongate member 33. According to one embodiment of the invention, an imaging cable 95 may be disposed in the middle of the optical fiber 88, with the optical fiber 88 also passing through the longitudinal lumen of the ring 76 and the longitudinal lumen 94 of the elongate member 33 toward the proximal end of the elongate member 33.

Fig. 6 also more clearly shows that the central lumen 94 of the elongated member 33 has a narrower cross-section near 96 the longitudinal tensioning lumen/groove 72.

According to one embodiment of the invention, the distal portion 98 of the elongate member 33 has a first durometer and the portion 100 of the elongate member 33 between the distal portion 98 and the proximal end 36 of the elongate member 33 has a second durometer that is higher than the first durometer. According to one embodiment of the invention, the elongate member 33 may be made of a single material, with the distal portion of the elongate member 33 including a series of cuts or grooves 102, with portions of the elongate member 33 removed along the tensioning lumen 72 along a plane generally perpendicular to the longitudinal axis 32 of the elongate member 33.

Details on other embodiments of how to make an elongated member 33 having two degrees of stiffness can be found in PCT application PCT/US2015/027170 entitled "steel MICRO-end" filed on 22/4/2015 and incorporated herein by reference.

Fig. 7 is an elevation view of the distal housing 86 with its proximal end attached to the distal end of the tension ring 76; two longitudinal recesses 80 cut out in the wall of the tension ring 76 from the proximal end of the tension ring 76. According to one embodiment of the invention, the longitudinal recess may be as long as or shorter than the tension ring 76. According to one embodiment of the invention, the tension ring 76 includes a lumen 104 through which lumen 104 the optical fibers and cables connected to the imaging sensors pass.

Fig. 8 includes, from left to right, side, front and longitudinal cross-sectional views of a distal housing 86 attached to the tension ring 76, according to one embodiment of the invention, showing exemplary dimensions according to one embodiment of the invention, wherein the outer diameter of the distal housing 86 is 1.5 mm; the inner diameter of the distal housing 86 is the same as the outer diameter of the tension ring, 1.35mm (1.5 mm outer diameter, 0.075mm wall thickness sheath); the inner diameter of the tension ring is 1.2 mm. According to one embodiment of the invention, the distal housing 86 and the tensioning ring 76 may be formed from two pieces of metal tubing attached together, or they may be turned together from a single piece of metal.

Fig. 9 is an elevation view of the distal housing 86 with its proximal end connected to the distal end of the tension ring 76 of fig. 8; two longitudinal recesses 80 are cut out from the proximal end of the tension ring 76 over the length of the wall of the tension ring 76, and the distal ends 78 of the tension wires 38 are welded into the recesses 80.

Fig. 10 includes, from left to right, a front view and a longitudinal cross-sectional view of distal housing 86 attached to tension ring 76 and to distal end 78 of tension wire 38; exemplary dimensions according to one embodiment of the invention are shown, wherein the outer diameter of the tension ring is 1.35mm and the diameter of the tension wire is 0.15 mm.

Fig. 11 includes, from left to right, side, front and longitudinal cross-sectional views of a distal housing 86 attached to a tension ring 76 according to another embodiment of the present invention, illustrating exemplary dimensions according to one embodiment of the present invention, wherein the outer diameter of the distal housing 86 is 1.5 mm; the inner diameter of the distal housing 86 is the same as the outer diameter of the tension ring, 1.35mm (1.5 mm outer diameter, 0.075mm wall thickness sheath); the inner diameter of the tension ring is 1.2 mm. According to one embodiment of the invention, the distal housing 86 and the tensioning ring 76 may be formed from two pieces of metal tubing attached together, or they may be turned together from a single piece of metal. According to the embodiment shown in fig. 11, the longitudinal recess 80 is cut along the entire length of the wall of the tension ring 76 from the proximal end to the distal end of the tension ring 76.

Fig. 12 includes, from left to right, a front view and a longitudinal cross-sectional view of distal housing 86 attached to tension ring 76 and to distal end 78 of tension wire 38; exemplary dimensions according to one embodiment of the invention are shown, wherein the outer diameter of the tension ring is 1.35mm and the diameter of the tension wire is 0.15 mm. Since the longitudinal recess 80 is cut along the entire length of the wall of the tension ring 76, the distal end 78 of the tension wire 38 may be welded along the entire length of the distal housing 86 and along the entire length of the tension ring 76.

Fig. 13 shows an axial cross-section of the elongated member 33 as shown in fig. 3 and 4 with a central lumen 31 and lateral longitudinal tensioning lumens 40 for passing tensioning wires (not shown). According to one embodiment of the invention, the central lumen 31 may have a narrower cross-section in the vicinity 66 of the longitudinal tensioning lumen 40.

Fig. 14 shows an axial cross-section of the elongated member 33 as shown in fig. 5 and 6, having a central lumen 94 and a recess 72 for passing a tension wire (not shown). According to one embodiment of the invention, the central lumen 94 may have a narrower cross-section in the vicinity 96 of the longitudinal tensioning lumen/groove 72.

Fig. 15A and 15B illustrate the process of attaching the distal end of the optical fiber 60 to an imaging sensor 54 having a rectangular (or square, as shown) cross-section.

The method comprises the following steps: disposing said distal end of optical fiber 60 in a space 106 comprised between wall 62 of imaging sensor 54 and an inner wall 108 of a mounting tube 110, the mounting tube 110 having an inner diameter equal to said diagonal of said rectangular cross-section, as shown at A-A in FIG. 12; permanently attaching the distal end of the optical fiber 60 to the imaging sensor 54, for example by introducing glue or resin 112 in the space existing between the fibers; and

after the glue or resin 112 has set, the mounting tube 110 is removed as shown at A-A in FIG. 12.

According to one embodiment of the present invention, after the distal end of the optical fiber 60 is attached to the imaging sensor 54, the distal end of the optical fiber 60 is polished together with the distal end of the imaging sensor 54 (e.g., including an optical window) so that light can be output by the polished end of the optical fiber 60.

The assembly 114 of the imaging sensor 54, the optical fiber 60, and the resin 112 may then be disposed at the end of the tension ring 44 and the elongated member 33, as shown in fig. 3, wherein the proximal end of the optical fiber, as well as the imaging cable attached to the proximal portion of the imaging sensor 54, passes through the central lumen of the tension ring 44 and the elongated member 33 before the assembly 114, the tension ring 44, and the elongated member 33 are covered in the sheath 58 as shown in fig. 3.

According to one embodiment of the invention, the inner diameter of the sheath 58 is equal to (or slightly larger than) the outer diameter of the assembly 114, the tensioning ring 44 and the elongated member 33. For example, insertion of an element having a given outer diameter into a sheath having the same (or slightly larger) inner diameter is described in detail in PCT application PCT/US2015/027170 entitled "steel MICRO-endo scope", filed on 22/4/2015, and incorporated herein by reference.

Fig. 16A is a front view of a tubular tension ring 44 such as shown in fig. 3 and 4 having two longitudinal recesses 48 cut in the inner wall of the tension ring and aligned with the longitudinal tension lumen 40 (not shown) of the elongated member 33 (not shown). The tubular tensioner ring 44 also comprises two axial recesses 50 (one shown) connecting the longitudinal recess 48 to a circumferential outer groove 52, the circumferential outer groove 52 being cut out on the outer wall of the tensioner ring 44. The distal ends of the two tension wires 38 pass through the longitudinal recess 48, the radial recess 50 and the circumferential outer groove 52, connecting in the groove 52. According to one embodiment of the invention, a single tensioning wire 38 may be bent into two, with the bends of the wire disposed in the channel 52 and the ends of the wire passing through the radial recesses 50, then through the longitudinal recesses 48, and then through the longitudinal tensioning lumens 40 (not shown) of the elongated member 33 (not shown).

Fig. 16B includes, from left to right, a side view and a cross-sectional view of a tubular tension ring 44 such as that shown in fig. 16A.

Fig. 17 includes, at its left-hand portion, an elevation view of a distal portion of a sheathed elongate member of an endoscope, using a distal housing 86 as described in detail with respect to fig. 5, 6, 11 and 12, in accordance with one embodiment of the present invention, wherein a longitudinal recess (not shown) is cut along the entire length of the wall of a tension ring (not shown), and the distal end 78 of the tension wire 38 extends to the distal end of the distal housing 86, and may be welded along the entire length of the distal housing 86. The embodiment shown in fig. 17 includes four tension wires arranged symmetrically along two perpendicular planes intersecting at the longitudinal axis of the elongated member. Another embodiment may include a different number of tension wires, such as two tension wires symmetrically arranged along a plane containing the longitudinal axis of the elongated member, where the plane may be parallel to both sidewalls of the imaging sensor 84.

According to one embodiment of the invention, the imaging sensor 84 having a rectangular cross-section comprises two juxtaposed

imaging sensors

84a, 84b having the same cross-section; for example for generating stereoscopic images. In the embodiment shown in fig. 17, the optical fibers 88 are shown disposed only along the two larger sides of the imaging sensor 84, but the optical fibers may be disposed along all sides of the imaging sensor, depending on the space available between the sides of the imaging sensor and the inner wall of the distal housing 86.

FIG. 17 includes, at its right-hand portion, an elevation view of the distal portion of the sheathed elongate member of an endoscope, similar to the embodiment shown at the left-hand side of FIG. 17, but with a distal housing 86 of non-circular cross-section, in accordance with another embodiment of the invention. According to the invention, the elongated member and the distal housing have the same longitudinal axis and have the same, non-circular cross-section, wherein the inner wall of the distal housing 86 is arranged around the longitudinal edge of the imaging sensor.

According to one embodiment of the invention, the imaging sensor 84 may also have a non-rectangular cross-section (not shown); the inner wall of distal housing 86 is arranged to surround the longitudinal edge of the imaging sensor.

FIG. 18 is a tissue diagram depicting a method of making the endoscope shown in FIG. 3 according to the present invention; the method comprises the following steps:

200 providing an imaging sensor having a rectangular cross-section; the proximal end of the imaging sensor is connected to the imaging cable;

202 providing a tension ring having an outer diameter equal to a diagonal of the rectangular cross-section, the ring having a central longitudinal lumen capable of receiving the imaging cable;

204 providing a flexible elongate member having an outer diameter equal to the diagonal of the rectangular cross-section, the flexible elongate member having at least a central longitudinal lumen capable of receiving the imaging cable and at least one lateral longitudinal tensioning lumen capable of receiving a tensioning wire;

206 attaching the distal ends of the tension wires to the tension ring;

208 passing said tensioning wire through said at least one tensioning lumen until the tensioning ring is disposed at the distal end of the flexible elongate member;

210 introducing the loop and the elongate member in an axial lumen of a flexible tubular sheath, wherein the sheath has an inner diameter equal to or slightly larger than the diagonal of the rectangular cross-section such that the loop extends beyond the distal end of the flexible tubular sheath;

212 passing the imaging cable through the longitudinal lumen of the ring and through the longitudinal lumen of the flexible elongate member from the distal end of the flexible tubular sheath;

214 introducing the imaging sensor in an axial lumen at a distal end of the flexible tubular sheath.

FIG. 19 is an organizational chart depicting possible additional steps of the method shown in FIG. 18, including:

216 passing proximal ends of the plurality of optical fibers through a space contained between a wall of the imaging sensor and an inner wall of the flexible tubular sheath and then through the longitudinal lumens of the loop and the elongate member;

218 arranging distal ends of the plurality of optical fibers to extend longitudinally along the imaging sensor in the space;

220 permanently attaching distal ends of the plurality of optical fibers in the space; and finally

222 polish the distal ends of the plurality of optical fibers attached to the imaging sensor along with the distal optical window of the imaging sensor.

FIG. 20 is a tissue diagram depicting a method of making the endoscope shown in FIG. 5 in accordance with the present invention; the method comprises the following steps:

224 providing an imaging sensor having a rectangular cross-section, a proximal end of the imaging sensor being connected to an imaging cable;

226 providing a tubular housing having an inner diameter equal to the diagonal of the rectangular cross-section; the proximal end of the tubular housing is attached to the distal end of a tensioning ring having an outer diameter smaller than the outer diameter of the tubular housing and having a central longitudinal lumen capable of receiving the imaging cable;

228 providing a flexible elongate member having an outer diameter equal to the outer diameter of the tensioner ring, the flexible elongate member having at least a central longitudinal lumen capable of receiving the imaging cable and at least one lateral longitudinal tensioning lumen capable of receiving a tensioning wire;

230 attaching the distal ends of the tension wires to the tension ring;

232 passing the tension wire through the at least one tension lumen;

234 introducing the ring and the elongate member in an axial lumen of a flexible tubular sheath, wherein an inner diameter of the sheath is equal to or slightly larger than an outer diameter of the ring and elongate member;

236 passing the imaging cable through the longitudinal lumens of the tensioning ring and the flexible elongate member; and

238 introduces an imaging sensor in the tubular housing.

FIG. 21 is an organizational chart depicting possible additional steps of the method shown in FIG. 20, including:

240 passing proximal ends of the plurality of optical fibers through a space contained between a wall of the imaging sensor and an inner wall of the tubular housing and then through the longitudinal lumens of the ring and the elongate member;

242 arranging distal ends of the plurality of optical fibers longitudinally along an imaging sensor in the space;

244 permanently attaching the distal ends of a plurality of optical fibers in the space; and finally

246 polish the distal ends of the plurality of optical fibers attached to the imaging sensor along with the distal optical window of the imaging sensor.

Fig. 22 is an elevation view of a steerable micro-device or endoscope 300 according to one embodiment of the present invention, including a cylindrical elongate member 12, such as described with respect to any of fig. 3-6 or 17, having a distal end and a proximal end 14, the elongate member 12 including at least a first lumen and a second lumen (e.g., lumen 40 of fig. 3 or lumen/groove 72 of fig. 5), a first tensioning wire extending within the first lumen and a second tensioning wire extending within the second lumen, the distal end of the tensioning wire attached to the distal end of the elongate member 12 (e.g., attached to the tensioning ring, the tensioning ring attached to the distal housing 86), and the proximal end of the tensioning wire exiting the lumen at the proximal end 14 of the elongate member 12.

According to one embodiment of the invention, the elongate member 12, the first and second lumens are arranged such that: the distal portion of the elongate member 12 bends in a first direction (a) when the proximal end of the first tensioning wire is pulled, and bends in a second direction (B) when the proximal end of the second tensioning wire is pulled. According to one embodiment of the invention, the proximal end 14 of the elongated member 12 is coupled to the handle 16 ', and the handle 16 ' and the elongated member 12 form a T-shaped arrangement, wherein the legs of the T are the elongated member 12 and the head of the T is the handle 16 '.

According to one embodiment of the invention, the handle 16' comprises a

rod

22A, 22B arranged: compressing a first portion 22A of the handle on one side of the proximal end 14 of the elongate member 12 (above the T-leg in fig. 22), pulling on the first tensioning wire; and compresses the second portion 22B of the handle 16' on the other side of the proximal end 14 of the elongate member 12 (below the T-leg in fig. 22) pulling on the second tensioning wire. According to one embodiment of the invention, the T-handle 16' may include a connector 24 for connecting a cable that allows the endoscope to be powered and/or pass a light beam onto an optical fiber and receive a video signal from an imaging sensor attached in the distal housing 86.

Fig. 23 is a partially open view of the steerable micro-device or endoscope shown in fig. 22. According to one embodiment of the invention, the handle 16' is sized and shaped such that: the handle 16 ' may be held in a user's hand with the proximal end 14 of the elongate member 12 passing through two fingers of the user's hand (e.g., the middle finger (major) and the little finger of the hand).

According to one embodiment of the invention, the handle 16' is sized and shaped such that: the side of the hand adjacent the index finger grips the grip on the handle 16' and compresses the first portion 22A of the handle; and the side of the hand adjacent the little finger grips the grip on the handle 16' and compresses the second portion 22B of the handle.

Fig. 23 shows that when the two

portions

22A and 22B of the rod are compressed, the proximal ends of the two

tensioning wires

38A, 38B are pulled, respectively.

According to one embodiment of the invention, as shown in fig. 23, the housing 16 'may alternatively include a connector 24, including a port 24' configured to pass through an imaging cable and optical fibers from an imaging sensor in the distal housing 86, with the distal ends of the optical fibers attached in the distal housing 86. According to one embodiment of the invention, a spiral (a screen wise) 302 may be provided to retain the cable and fiber in the housing 16'.

The device according to the invention, which has a camera and an optical fiber for transmitting light, is particularly suitable for use as a microendoscope in the medical field, but can also be used in the automotive field or in the home furnishing field for viewing difficult to reach places.

The applicant has disclosed the state of the art but has also considered advancements which future adjustments may take into account, i.e. in accordance with the state of the art at the time. It is intended that the scope of the invention be defined by the written and applicable equivalents of the claims. The singular reference of an element in the claims does not mean "one" or "only one" unless explicitly so stated. Furthermore, no element, component, method, or process step disclosed herein is intended to be dedicated to the public regardless of whether the element, component, or step is explicitly recited in the claims. Any required element herein should not be construed in accordance with the provisions of 35u.s.c.112, paragraph six, unless the element is specifically defined using the phrase "means for …", and no method or process step herein should be construed in accordance with such provisions, unless the step or steps are specifically defined using the phrase "including the step(s) of..)" to include the step(s).

Claims

1. An endoscope, comprising:

a tubular elongated member having a longitudinal axis, a proximal end, and a distal end;

at least one tensioning wire disposed in a tensioning lumen along one side of the elongate member between the proximal and distal ends of the elongate member; and

a head disposed at a distal end of the elongated member, the head comprising:

a tubular tension ring attached to a distal end of the tension wire, the tension ring having the same outer diameter as the elongated member;

wherein a tubular sheath is fitted over the elongated member and the tensioning ring of the head;

a proximal end of the tension ring abutting a distal end of the elongated member; and

the tensioning lumen of the elongate member is a longitudinal groove cut in the outer surface of the elongate member; the tension wires are retained in the groove by the tubular sheath.

2. The endoscope of claim 1, wherein the distal housing of the head has an outer diameter that is the same as an outer diameter of the tubular sheath.

3. The endoscope of claim 1, wherein the head comprises an imaging sensor having a rectangular cross-section disposed at a distal end of the head; and

a tubular distal housing disposed longitudinally around the imaging sensor, the distal housing having an inner diameter that is the same or slightly larger than a diagonal of the rectangular cross-section of the imaging sensor;

wherein the distal housing has a proximal end attached to a distal end of the tensioning ring.

4. The endoscope of claim 3, wherein a distal end of a plurality of optical fibers is disposed between an inner diameter of the distal housing and a sidewall of the imaging sensor; the optical fiber passes through a lumen in the tension ring and a lumen in the elongate member.

5. The endoscope of claim 1, wherein the tensioning ring comprises a longitudinal slit extending from a proximal end of the tensioning ring; a distal end of the tension wire extends along the longitudinal cut and is welded thereto such that the tension wire does not extend radially beyond the outer diameter of the tension ring.

6. The endoscope of claim 1, wherein the elongated member comprises a central lumen; the central lumen has a narrower cross-section opposite the longitudinal groove in the outer surface of the elongate member.

7. The endoscope of claim 1, wherein the elongated member comprises two tensioning lumens and two tensioning wires arranged symmetrically with respect to the longitudinal axis of the elongated member.

8. The endoscope of claim 3, wherein the distal housing is formed by a distal end of the tubular sheath; the tubular sheath encases the elongated member, the tensioning ring of the head, and the imaging sensor.

9. The endoscope of claim 8, wherein the elongated member comprises two longitudinal tensioning lumens and two tensioning wires arranged symmetrically with respect to the longitudinal axis of the elongated member.

10. The endoscope of claim 9, wherein the tensioning ring comprises:

two longitudinal recesses cut in an inner wall of the tension ring and aligned with the longitudinal tension lumens of the elongated member; and

two radial recesses connecting the longitudinal recess to a circumferential outer groove cut in an outer wall of the tension ring;

the distal ends of the two tension wires are arranged in the two longitudinal recesses and the two radial recesses and are connected in the circumferentially outer groove.

11. The endoscope of claim 1, wherein the distal portion of the elongated member has a first hardness; a portion of the elongate member between the distal portion and the proximal end of the elongate member has a second durometer that is higher than the first durometer.

12. The endoscope of claim 11, wherein the elongated member is made of a single material; the distal portion of the elongate member includes a series of cuts or recesses that remove portions of the elongate member along the tensioning lumen along a plane that is substantially perpendicular to the longitudinal axis of the elongate member.

13. A method of manufacturing an endoscope, comprising:

providing a tension ring having a first outer diameter and a first central longitudinal lumen;

providing a flexible elongate member having an outer diameter equal to the first outer diameter of the tension ring; said flexible elongate member having at least one tensioning lumen along one side of said elongate member, said tensioning lumen of said elongate member being a longitudinal groove cut into an outer surface of said elongate member between a proximal end and a distal end of said elongate member; and a second central longitudinal lumen;

introducing the elongate member into an axial lumen of a flexible tubular sheath, wherein an inner diameter of the sheath is equal to or slightly larger than the first outer diameter;

attaching a distal end of a tension wire to the tension ring;

passing the tensioning wire through the at least one tensioning lumen until the tensioning ring is disposed at the distal end of the flexible elongate member beyond the distal end of the flexible tubular sheath such that the tensioning ring is located inside the flexible tubular sheath beyond the distal end of the flexible tubular sheath.

14. The method of claim 13, further comprising:

providing an imaging sensor having a rectangular cross-section with a diagonal equal to the first outer diameter; the proximal end of the imaging sensor is connected to an imaging cable;

passing the imaging cable through a first central longitudinal lumen of the tensioning ring and through a second central longitudinal lumen of the flexible elongate member from a distal end of the flexible tubular sheath; and

introducing the imaging sensor into the axial lumen of the distal end of the flexible tubular sheath.

15. The method of claim 14, further comprising:

passing proximal ends of a plurality of optical fibers through a space contained between a wall of the imaging sensor and an inner wall of the flexible tubular sheath and then through the tensioning ring and first and second central longitudinal lumens of the elongated member;

arranging distal ends of the plurality of optical fibers to extend longitudinally in the space along the imaging sensor;

and permanently attaching distal ends of the plurality of optical fibers in the space.

16. The method of claim 15, comprising polishing distal ends of a plurality of optical fibers attached to the imaging sensor along with a distal optical window of the imaging sensor.

17. The method of claim 13, comprising:

providing an imaging sensor having a rectangular cross-section with a diagonal equal to the first outer diameter, with a proximal end of the imaging sensor connected to an imaging cable;

wherein providing a tension ring comprises providing a tubular housing having an inner diameter equal to or slightly larger than a diagonal of the rectangular cross-section; a proximal end of the tubular housing attached to a distal end of the tensioning ring, the tensioning ring having a first central longitudinal lumen configured to receive the imaging cable;

passing the imaging cable through a first central longitudinal lumen of the tensioning ring and a second central longitudinal lumen of the flexible elongate member;

and introducing the imaging sensor into the tubular housing.

18. The method of claim 17, wherein an outer diameter of the sheath is equal to an outer diameter of the tubular housing.

19. The method of claim 17, further comprising:

passing proximal ends of a plurality of optical fibers through a space contained between a wall of the imaging sensor and an inner wall of the tubular housing and then through the tensioning ring and first and second central longitudinal lumens of the elongated member;

arranging distal ends of the plurality of optical fibers longitudinally along the imaging sensor in the space; and

distal ends of the plurality of optical fibers are permanently attached in the space.

20. The method of claim 19, comprising polishing distal ends of a plurality of optical fibers attached to the imaging sensor along with a distal optical window of the imaging sensor.